Non-staling chewing gum compositions and improved method of preparation

ABSTRACT

A chewing gum composition and process whereby the process comprises softening the base between a temperature range of about 40° C. to about 60° C.; admixing softening agents, sweetening agents and flavoring agents; extruding the composition prior to cooling; forming the composition into suitable chewing gum pieces without cooling; and immediately wrapping the pieces with a minimum of protective wrapping without prior conditioning. No moisture or moisture-containing ingredients are used in the process or added to the ingredients and the chewing gum composition has a final moisture content of up to about 0.9% by weight.

This application is a continuation-in-part of copending U.S. Ser. No.644,734, filed Aug. 27, 1984.

The present invention concerns a novel chewing gum composition andmethod of preparation and more particularly to naturalsweetener-containing chewing gum compositions being substantially freefrom water and having advantageous process characteristics and shelflife stability. The chewing gum compositions form chewing gums whichhave exceptionally long periods of shelf life without protectivepackaging and without the use of humectics as traditionally used in theart.

The present invention also concerns a chewing gum composition which,unlike those of the prior art, can be processed using fewer steps,thereby saving time and production costs. The process of the presentinvention does not require such traditional process steps as cooling andconditioning (setting), nor does it require specified relative humidityconditions for coated gums, as does the prior art. Additionally, noprotective wrapping is necessary to maintain freshness. The inventivecompositions do not require water or moisturecontaining additives inorder to obtain a formulation viscosity which is manageable andhomogeneous, and which ultimately yields a chewing gum product which hasexcellent texture, mouthfeel and organoleptic properties. The presentcompositions, when prepared in the specified manner, have the juiciness,flavor, texture, mouthfeel and other organoleptic characteristics of theprior art, which uses moisture or moisture-containing ingredients toachieve these characteristics.

Another advantage of the instant invention is that those ingredientswhich are ordinarily unstable in the presence of moisture, e.g.,aspartame, do not present a problem, since the inventive compositionsare substantially anhydrous. Thus, such traditionally moisture-unstableingredients can be added without fear of deterioration or instability.

Another advantage to the instant invention is that gum product formedfrom the inventive compositions and using the inventive method can bewrapped immediately after forming without the need for conventionalcooling followed by conditioning for 24 to 48 hours. The inventivecompositions can be wrapped immediately within 2 hours of rollingwithout fear of wrapping materials adhering to the chewing gum product.

Another advantage of the instant invention is that chewing gum productsformed by means of the inventive process and containing the inventivecompositions can remain without wrapping or protective covering atambient temperatures for longer periods of time than traditional chewinggums without going stale, becoming tacky or showing instability. Thus,the inventive compositions retain their freshness for up to a year ormore without the need for protective, hermetic wrappings.

Other advantages of the inventive compositions and process ofpreparation will become apparent from the detailed description providedherein.

Conventional chewing gum process steps disclosed in the prior artordinarily involve formulating the chewing gum composition attemperatures between about 70° to 120° C., followed by cooling,extruding, forming into gum pieces and finally conditioning (setting)for 24 to 48 hours. Additionally, if the chewing gum is to be a hardsugar-coated gum piece (e.g., a pellet or ball), usually 48 hours ofconditioning at 66°-70° F./RH 47-55%, is required prior to theapplication of the coating. It is traditionally necessary to apply thecoating under controlled temperature conditions (80°-85° F.) at lowrelative humidity (RH 24-40%). These conditions must be maintainedclosely or serious processing problems result. For example, changes inthe temperature and humidity outside these ranges cause softening of thegum and deformation of shape which makes coating difficult. This problemhas been well known for many years and is especially harmful in areaswith extreme climates such as the tropics. If the chewing gum is formedas a slab or stick gum, one prior art method required immediatelywrapping the gum subsequent to 24-48 hour conditioning such that the gumproduct would retain its freshness.

Additionally, conventional gum processes, which use traditional highspeed wrapping machines (e.g., 800-1800 sticks or slabs per minute),require the wrapping to be done at controlled temperature and humidityconditions. If the temperature or humidity becomes too high, the chewinggum composition would stick to the rollers and cutters. The individualgum pieces would be wrapped in air-tight packages and usually thosewould be placed in larger boxes which themselves would be sealed to keepout air and moisture. In spite of all these precautions duringprocessing, conventional chewing gum tends to stick to wrappers at hightemperatures and to become brittle at low temperatures during storage.Additionally, conventional mint flavored chewing gum and some fruitflavors undergo oxidation of the flavors due to the interaction of theflavor with the base in the presence of moisture. The results is a staleproduct. The instant moistureless chewing gum compositions and processof preparation solve these problems.

As stated above, the inventive process does not require all of theprocess steps of the prior art. The chewing gum compositions once formeddo not have to be cooled prior to formation into gum pieces, norconditioned prior to wrapping. These advantages are due to the specificand novel formulations presented herein.

The prior art has disclosed chewing gum compositions which have lowpercentages of moisture in the final product. For the most part, theprior art has concentrated on driving off the water once the chewing gumformulation has been made. Thus, the prior art compositions ordinarilycontain water and/or moisture-containing ingredients, e.g., sorbitolsolution, corn syrup solutions, etc., and would therefore requireheating or purification of the composition to drive off water and obtaina certain moisture content. For example, U.S. Pat. No. 4,035,572involves a gum base formulation with less than 0.5% moisture. This lowpercentage of moisture is due to the purification process which removeswater and solvent from the gum base.

U.S. Pat. No. 4,382,963 involves a low calorie chewing gum which usespolydextrose as the sole soluble bulking agent. The moisture content inthe final product is about 1 to 5% and this is obtained by omitting theaqueous component, e.g., sorbitol syrups or corn syrups, which isnormally used in chewing gum products.

U.S. Pat. No. 3,262,784 concerns a chewing gum composition has less than1% moisture in the final product due to heating between about 170° and250° F. to drive off the water.

U.S Pat. No. 4,150,161 concerns a two component confection having acarbonated candy component and a pliable bubble gum component with eachcomponent having a controlled water activity between 0.1 to 0.3 andwhich is capable of surviving long periods of storage when packaged in amoisture resistant material.

Conventional chewing gum formulations generally have a molten chewinggum base, resins, waxes, fillers, emulsifiers, an aqueous sugar syrup(corn syrup or sorbitol syrup), dry sugar (sucrose or dextrose) andflavor. The aqueous sugar syrup or non-sugar syrup has always beenbelieved to be a necessary component, as far as conventional commercialmanufacture is concerned. As a result, the chewing gum product wouldordinarily contain 2% to 7% by weight of moisture. Moreover, ingredientssuch as humectant were often required in order to retain the moisture ofthe chewing gums and obtain a reasonable commercial shelf life, therebyinsuring freshness to the purchaser. The compositions of the instantinvention do not use humectants (moisture-retaining ingredients) noraqueous solutions (moisture-containing ingredients) and therefore do notsuffer from loss of moisture to the atmosphere.

The chewing gum compositions of the instant invention have a moisturecontent of up to about 0.9% by weight of the final composition andcomprise a gum base which softens in a temperature range of about 40° toabout 60° C., a flavoring agent, preferably but optionally absorbed inthe microporous channels of water-soluble spherical particles, a solidwater-soluble sweetening agent, said ingredients containing onlyresidual moisture and being added to the composition without additionalmoisture, i.e. without the use of aqueous solutions. The final chewinggum composition has an equilibrium relative humidity value lower thanthe ambient relative humidity.

There are several critical aspects to the instant invention. One suchcriticality is the requirement of a soft gum base, e.g., one whichsoftens in the temperature range disclosed above. Traditionally, gumbases were employed which melted in a range of 70°-120° C. While the gumbases of the instant invention are well known in the art, they must notbe heated beyond the softening point of 60° C. Thus, while variouscombinations of these known soft gum bases may be used, the particularcombination employed must not be such that its softening point is aboveabout 60° C.

Another such criticality is the total moisture content and theequilibrium relative humidity value of the chewing gum composition.Moisture related product degradation is one of the prime stabilityconcerns for chewing gum compositions and products. The environmentalfactor influencing moisture loss or gain is relative humidity. It iscommonly accepted that the lower the relative humidity, the fasterthings dry out. Relative humidity (RH) is a measure of the vaporpressure exerted by the moisture in the atmosphere. As relative humidityincreases or decreases, the pressure of the moisture in the atmosphereincreases or decreases accordingly. Pure water exerts a moisture vaporpressure equivalent to 100% RH. As such, that water will evaporate whenstored in any environment less than 100% RH. If impurities are added tothat water, the moisture vapor pressure will decrease.

Equilibrium relative humidity (ERH) measurements were taken for theinventive compositions. ERH is a means of identifying the susceptibilityor propensity of the composition to moisture gain or loss, which in turnrelates to the tendency for the gum to remain moisture-stable and to notdry out or become stale. When the product neither picks up nor losesmoisture, it is in a state of equilibrium with the environment. The ERHmeasurement depends on the ratio of free moisture to bound moisture in aproduct and the temperature. The amount and rate at which a chewing gumloses or gains moisture depends on the differential between theproduct's ERH and ambient RH. The transfer of moisture will be in thedirection from high to low RH until an equilibrium state is reached.

The inventive chewing gum compositions have a low ERH and thereforetends not to lose moisture, since most environments have a higher RHthan the compositions ERH. For example, the RH of most geographicregions is between 35-45% depending on the time of year. If the ERH ofthe chewing gum is greater than the ambient relative humidity, the gumwill lose moisture and dry out. The ERH range of the inventivecompositions, however, are between about 15% to about 30%, andpreferably about 21 to about 25% at room temperature, e.g. about 23° C.Thus, there is no tendency for chewing gum made from the inventivecompositions to dry out. Rather, the tendency, if any, would be to pickup moisture during shelf life. Too much moisture pick up is undesirablehowever, since it causes wetting of the gum, loss of sugar coating andwater solubles and ultimately sticking of the wrapper to the gum. Thus,a delicate moisture balance must be maintained whereby the product's ERHis maintained at a low value relative to the ambient relative humidity;and the total moisture content kept at a maximum of about 0.9% byweight, and preferably about 0.3%. Thus, the advantages of the instantchewing gum compositions of long shelf life and freshness stability, isbelieved to be due to the critical aspects of:

(a) omitting moisture and moisture containing ingredients in the chewinggum formulations;

(b) maintaining the ERH of the chewing gum composition at a lower levelthan the ambient relative humidity; and

(c) using a gum base which softens between the temperatures of about 40°C. and 60° C.

The inventive chewing gum compositions preferably but optionally containan edible good material which is capable of being formed into particleshaving microporous channels. Flavoring liquid is absorbed into themicroporous channels of the particles. The products have preferred lowbulk densities in the range of about 3.0 to about 8 lb./ft.³ andpreferably about 3.0 to about 6.0 lb./ft.³ . Materials, not having lowbulk densities, coupled with microporous channels have been found notsuitable for use in the inventive formulations. Such materials have beenfound to quickly release the flavoring from the formulation and fail tosustain flavor-sweetness duration. U.S Pat. No. 4,497,832 discloseschewing gums having flavor sorbed in the microporous channels ofspherical particles wherein the channels increase the sorptive surfacearea. These gum compositions, however, lack the additional criticalitiesof the instant invention.

The optionally included spherical particles of the invention may beproduced from a wide range of materials. Without being limited thereto,illustrative materials are carbohydrates such as the dextrins, starch,pectin, algin, methyl cellulose, carboxy methyl cellulose, carboxymethyl amylose, carboxy methylamylopectin, dextrose, fructose, maltose,lactose, dextrins, natural gums and mixtures thereof. Exemplary naturalgums include tragacanth, acacia, arabic, locus bean, caraya, andcarragean. The fine, porous nature of the spherical particlesimmediately absorb moisture from saliva when the chewing gum product ismasticated. The particles swell and import a juiciness to the gum.

Such materials are commercially available and may be prepared by anumber of methods. Once such method involves spray drying previouslyexpanded particles in a heated zone. For illustrative purposes, however,a preferred process for preparing the spherical particles useful in theinstant formulations is described in U.S. Pat. No. 80,593 to Cohan,which reference teachings are incorporated herein by reference. Brieflythe reference process involves spraying a flowable composition in thepresence of a blowing agent, such as ammonium bicarbonate or othersubstance capable of becoming gaseous in situ, to form beads, subjectingthe beads to a heated zone to expand the beads by expansion of gaseswithin the interior of the beads, and cooling the resulting expandedbeads to stop further expansion and aid in control of bulk density.Carbon dioxide and nitrogen are other useful blowing agents.

Another useful method of producing materials having microporous channelsis disclosed in U.S. Pat. No. 4,310,560, wherein finely dividedparticulate edible materials which acquire surface stickiness whenmoistened are mixed with a leavening system containing sodiumbicarbonate and a leavening acid. This mixture is sprayed with anaqueous liquid while the particulate materials are tumbled and rolled toform agglomerates. The agglomerates are then heated with a hot airstream between 51°-135° C. to cause the release of carbon dioxide gasfrom the leavening system. The release of the gas causes the finalparticles to be porous in nature.

The spherical particles are employed in the chewing gum composition inamounts of about 0.1% to about 12% by weight and preferably about 0.5%to about 6% by weight based on the weight of the final formulation.Amounts less than 0.1% fail to achieve enhanced flavor and sweetnessperception whereas amounts higher than 12% does not achieve a pleasingflavor sweetness release.

The preferred spherical particle for use with this invention is amaltodextrin. This maltodextrin is distinct from known maltodextrinswhich have distinct particle sizes and are void of a microporous channelstructure. Such conventional maltodextrins or corn syrup solids as theyare commonly referred to, have bulk densities from 15 to 46 lb./ft.³ andD.E. values from 7 to 38. Such materials are unsuitable for use in thepresent invention in lieu of the microporous particles. It should berecognized that such maltodextrins may be used in the instantformulations in addition to the spherical microporous particles. Whenused in this manner, they may be used in conventional amounts well knownto the skilled inventor.

Flavoring agents well known to the chewing gum art may be added to thechewing gum compositions of the instant invention. These flavoringagents may be chosen from synthetic flavor oils, flavorings and/or oilsderived from plants, leaves, flowers, fruits and so forth, andcombinations thereof. Representative flavor oils include: spearmint oil,cinnamon oil, oil of wintergreen (methylsalicylate) and peppermint oilsas well as their flavoring replacements. Also useful are artificial,natural or synthetic fruit flavors such as citrus oil including lemon,orange, grape, lime and grapefruit and fruit essences including apple,strawberry, cherry, pineapple, banana and so forth. Other fruit flavorswell known to the art are also employable. Mixtures can be employed.

The amount of flavoring agent employed is normally a matter ofpreference subject to such factors as flavor type, base type andstrength desired. In general, amounts of about 0.05% to about 3.0% byweight of the final chewing gum composition are useable with amounts ofabout 0.3% to about 1.5% being preferred and about 0.7% to about 1.2%being most preferred.

Those elastomers useful in the soft gum bases of instant inventioninclude, but are not limited to, isobutylene-isoprene copolymers,polyvinylacetate, polyisobutylene, polyvinylalcohol, SBR, naturalrubbers such as chicle, jelutong, balata, crown gum, guttapercha,lechi-caspi, sorva and the like and mixtures thereof. When using acombination of elastomers, the total elastomer mixture must be capableof being softened within the range of about 40° C. to about 60° C.,preferably about 45° to about 57° C., and most preferably about 50° toabout 55° C. The process of softening is meant to be distinct from thetraditional melting of gum bases. By the term "softened" is meant thegum base is heated to a semi-viscous state, wherein the viscosity isrelatively high and the base has better film forming and stretchingcharacteristics than bases which are melted. Additionally, the lowertemperature used to soften the base does not melt the sugar and othermaterials added to the gum base and as such there is believed to belittle chemical interaction between the base and these materials. Theconventional bases on the other hand, are heated to higher temperaturesto cause the gum base to liquify (melt). The melted base has a muchlower viscosity than the inventive softened bases and as such has lessof a film forming, stretching quality. Additionally, sugars anddissolvable materials also melt along with the elastomers. Thesematerials often recrystallize out later on, making the product brittle.

The amount of gum base employed will vary greatly depending on variousfactors such as the type of base used, consistency desired and othercomponents used to make the final product. In general, amounts of about5% to about 65% by weight of the final chewing gum composition areacceptable for use, with preferred amounts of about 15 to about 40% andmore preferably about 18% to about 35% by weight being suitable.

The gum base composition may contain elastomer solvents to aid insoftening the rubber component. It is important, however, that thesecomponents be substantially free from water, since the final compositionis to have a maximum moisture content of about 0.3% by weight. Suchelastomer solvents may comprise the methyl, glycerol or pentaerythritolesters of rosins or modified rosins, such as hydrogenated, dimerized orpolymerized rosins or mixtures thereof. Examples of elastomer solventssuitable for use herein include pentaerythritol ester of partiallyhydrogenated wood rosin, pentaerythritol ester of wood rosin, glycerolester of partially dimerized rosin, glycerol ester of polymerized rosin,glycerol ester of tall oil rosin, glycerol ester of wood rosin andpartially hydrogenated wood rosin, and partially hydrogenated methylester of rosin and mixtures thereof. The solvent may be employed in anamount ranging from about 10% to about 75% and preferably about 45% toabout 70% by weight of the gum base.

A variety of traditional ingredients used as plasticizers or softenerssuch as lecithin and the like, may also be incorporated into the gumbase to obtain a variety of desirable textures and consistencyproperties. These additional materials are generally employed in amountsof up to about 30% by weight and preferably in amounts of from about 3%to about 7% by weight of the final gum base composition. Mixtures ofsuch ingredients can be used.

The chewing gum compositions generally contain a major portion of asolid natural sweetening agent selected from the group consisting ofmono-,di- and polysaccharides and mixtures thereof. Other drywatersoluble artificial sweetening agents may be used in conjunctionwith the solid natural sweeteners. The term "natural" sweetenersincludes naturally occuring sweeteners which are artificially made, aswell as those which naturally occur. Without being limited to particularsweeteners, representative illustrations encompass:

A. Water-soluble natural sweetening agents such as monosaccharides,disaccharides, and polysaccharides such as xylose, ribose, glucose,mannose, galactose, fructose, dextrose, sucrose, sugar, maltose;polyhydric alcohols such as sorbitol, mannitol, xylitol; and mixturesthereof.

B. Water-soluble artificial sweeteners such as the soluble saccharinesalts, i.e., sodium or calcium saccharin salts, cyclamate salts,acesulfame-K and the like, and the free acid form of saccharin.

C. Dipeptide based sweeteners such as L-aspartyl-L-phenylalanine methylester and materials described in U.S. Pat. No 3,492,131 and the like.

The water-soluble solid natural sweeteners described in category Aabove, are preferably used in amounts of about 25% to about 75% byweight and most preferably from about 50% to about 65% by weight of thefinal chewing gum composition. In contrast, the artificial sweetenersdescribed in categories B and C are used in amounts of about 0.005% toabout 5.0% and most preferably about 0.05% to about 2.5% by weight ofthe final chewing gum composition. These amounts are ordinarilynecessary to achieve a desired level of sweetness independent from theflavor level achieved from flavor oils.

The chewing gum compositions of this invention may additionally includethe conventional additives of coloring agents such as titanium dioxide;additional fillers such as aluminum hydroxide, alumina, aluminumsilicates: gum base fillers such as talc and calcium carbonate andcombinations thereof; and additional emulsifiers such as glycerolmonostearate. The amount of filler in the gum base should remain withinthe range of about 10 to about 25% by weight of the gum base.

The inventive process of making a chewing gum comprises the steps of:

(a) softening the gum base using a temperature in the range of about 40°C. to about 60° C.;

(b) admixing a sweetening agent and a flavoring agent, said flavoringagent being absorbed in the microporous channels of water-solublespherical particles continuing to mix until a homogenous, pliablemixture is obtained;

(c) extruding the composition prior to cooling;

(d) forming the composition into suitable chewing gum pieces withoutcooling; and

(e) wrapping without prior conditioning the substantially moisturelesschewing gum.

The gum bases of the inventive compositions and process, due to theirunique softening characteristics between the ranges disclosed above, canbe made in most chewing gum mixing kettles without the specialrequirements of traditional gum base kettles.

FIG. 1 shows both the current (prior art) commercial process of makinggum base, as well as the inventive process. Whereas the prior artprocess required masticating and melting of the gum base in a two-stepstarting batch/finished batch process usually requiring 5-6 hours, theinventive process requires only softening of the gum base in a one-stepprocess taking about 1-11/2 hours. It is significant that the inventiveprocess saves considerable time and energy over the prior art processsince this saving can be reflected in significant cost savings, moreefficient production, as well as a higher quality chewing gum.

FIG. 2 shows processes for making chewing gum for the prior art. Asdepicted, the prior art melts the gum base, mixes in other chewing gumcomposition ingredients, and cools the mixture prior to extrusion.Additionally, prior to wrapping, the prior art compositions areconditioned for 24-48 hours.

The inventive process depicted in FIG. 3, however, does not requirecooling prior to extrusion, nor does it require conditioning prior towrapping. This process can be modified by softening the base directly inthe gum kettle, followed by extruding, rolling and scoring and wrapping.Additionally, the gum base can be first softened by other means such asin an oven, then placed in the kettle and extruded.

The inventive chewing gum compositions and the inventive process aremutually dependent on one another and the benefits of the invention as awhole result from this mutual dependence. Thus, the gum base must have asoftening range of between about 40° C. and about 60° C. to be useful inthe inventive process. Additionally, to be able to carry out the processas described, no additional moisture is added. The only moisture presentis residual moisture, most of which is believed to be bound moisture,inherent in certain ingredients. The total residual moisture must notyield a chewing gum composition and product outside of the rangerecited. Thus, the final chewing gum composition has a moisture contentof up to about 0.9% by weight without any processing steps directed todrying or removing of moisture. The term substantially moisturelessrefers to this moisture content.

Chewing gum products made by the inventive process and using theinventive formulations have remained fresh, soft and pliable for oneyear or more with a minimum of protective packaging. For example,unwrapped sticks of chewing gum have remained soft, pliable and haveretained their quality and freshness for a year or more in the open airor in unsealed pouches. This advantage is attributable to thecombination of chewing gum ingredients processed in the mannerdescribed.

The instant invention therefore contemplates a chewing gum compositionwhich remains fresh for a year or more with a minimum of protectivewrapping, having a moisture content of up to about 0.9% by weight andbeing capable of being extruded, formed, coated and wrapped withoutcooling or conditioning, said composition comprising:

(a) a gum base having a softening range of about 40° C. to about 60° C.;

(b) a flavoring agent and a sweetening agent absorbed into themicroporous channels of water-soluble spherical particles; saidingredients containing only residual moisture; said composition having aequilibrium relative humidity lower than the ambient humidity and saidcomposition being prepared by the process comprising:

(i) softening the gum base in a temperature range of about 40° C. toabout 60° C.;

(ii) admixing sweetening agents and flavoring agents:

(iii) extruding the composition;

(iv) forming the composition into suitable

(v) wrapping the pieces without prior conditioning.

The instant inventive compositions in combination with the inventiveprocess may be formed into stick, slab, pellet, pillow, center-filled,chunk, sugar-coated or other gum form.

The following examples are given to illustrate the invention, but arenot deemed to be limiting thereof. All percentages given throughout thespecification are based upon weight unless otherwise indicated.

EXAMPLE ONE

Table I shows various chewing gum formulations of the instant inventionas well as those of the prior art.

Chewing gum pieces were made using inventive formulations A-J and usingthe inventive process described above. The freshly made gum pieces werethen tested for taste, chew, texture, softness, flavor, sweetness andother organoleptic characteristics by a group of expert panelists. Thefreshly made gum was judged to be as good or better than the comparablecommercial chewing gums.

Other freshly made gum pieces were put through a series of stabilitytests including naked exposure to air for long periods of time,accelerated aging tests, humidity tests, cycling tests and so forth, allof which are described below.

                  TABLE I                                                         ______________________________________                                        SUGAR CHEWING GUM FORMULATIONS                                                (% by weight of total composition)                                                   Prior Art                                                                             Inventive                                                      Ingredients                                                                            I      II     A    B    C    D    E    F                             ______________________________________                                        Gum Base 21     25     37.5 28.0 31   20   31   25                            Corn Syrup                                                                             16     20     --   --   --   --   --   --                            (aqueous                                                                      solution)                                                                     Sugar    60.8   51.1   51..sup.1                                                                          66.3.sup.2                                                                         67.0 70   --   41                            Dextrose*                                                                              --     --     6.0  --   --   --   65   20                            Fructose --     --     --   --   --   --   --   10                            Softener 0.7    2.0    0.25 0.3  0.5  1.0  1.0  1.0                           Flavor   1.5    1.9    1.5  1.35 1.5  1.0  1.5  1.5                           Spherical                                                                              --     --     4.0  3.0  --   8    --   --                            particles                                                                     having                                                                        micropores                                                                    Gum arabic                                                                             --     --     --   --   --   --   2    1.5                           powder                                                                        ______________________________________                                         *Powdered mixture (fine and/or course)                                        .sup.1 Actual value 50.975                                                    .sup.2 Actual value 66.35                                                

                  TABLE II                                                        ______________________________________                                        SUGARLESS CHEWING GUM FORMULATIONS                                            (% by weight of total composition)                                            Prior Art       Inventive                                                     Ingredients                                                                           III      IV     G      H    I       J                                 ______________________________________                                        Gum Base                                                                              20       30     28     22   35      50                                Sorbitol                                                                              12       8      --     --   --      --                                solution                                                                      Sorbitol                                                                              65.7     50.35  53.9   50.8 54.975  29.8                              powder                                                                        Mannitol                                                                              --       5.0    8      12   --      10                                powder                                                                        Softener                                                                              1.0      5.0    10     15   8       10                                Sweetener                                                                             0.1      0.15                                                         Flavor  1.2      1.5    0.1    0.2  0.075   0.2                               ______________________________________                                    

Non-Staling Test

Unwrapped chewing gum pieces made by the inventive process and usingeach of the inventive formulations A-J (Tables I and II) were allowed tosit in open air at ambient temperature for 12 months.

Other commercially available comparable chewing gum pieces were allowedto stand in the same manner and at the end of this period compared tothe inventive chewing gum products by an expert panel. The commerciallyavailable chewing gum products were found upon visual inspection to becracked, hard and brittle. Chewing was difficult and flavor and textureexhibited a stale quality. Overall, the prior art chewing gum was foundto be undesirable and unfit for consumption.

The chewing gum products of the instant invention, however, retainedtheir flexibility, softness and flavor and tasted fresh as if newlymade.

Accelerated Aging Tests

Unwrapped chewing gum sticks formed from the inventive process and usinginventive formulations A-C were exposed unwrapped at 23° C./25% RH for2, 4, 6, 8, 12, 16 and 26 weeks. The current comparable commercialchewing gum was subjected to these same environmental tests.

Subsequent to exposure the chewing gum pieces were evaluated forhardness using an Instron machine. The gum piece is held in placeimpaled with a plunger apparatus connected to the instron arm, and thehighest point of resistance before the gum piece fails is recorded inpounds. The harder, e.g., the more stale and brittle the gum piece is,the more force is required to enter the gum. It is this force (pounds)which is taken as the indicator of the hardness of the gum.

The results of these tests, shown graphically in FIG. 4, indicate theinventive formulations made by the inventive process retain theirflexibility and softness as reflected by the nearly constant results ofthe hardness tests. The inventive formulations remained soft andflexible and had the organoleptic properties of freshly made gum evenafter 26 weeks at 23° C./23% relative humidity.

As indicated in the same figure, the commercial doublemint productsteadily became harder and after 8 weeks was over 4 times harder, andtherefore staler, than the inventive product after 26 weeks.

FIG. 5 shows inventive formulations A & B having been formed into slabchewing gum and compared with conventional, commercially available slabchewing gum under the same conditions as above (23° C./23% RH). Theresults demonstrate that the inventive product retains its softness,indicated by little change of its hardness over time. The competitiveproduct, on the other hand, clearly becomes much harder over time,indicting its proneness to staling.

FIG. 7 shows the results of the accelerated aging tests conducted in thesame manner on sugarless gum. The results after 22 weeks indicates thatthe inventive compositions are comparable to the current commercialproducts in retention of softness and flexibility as reflected byinsignificant changes over time in hardness.

Quantitative Determination of Moisture Pick-up

Chewing gum pieces made from each of the inventive formulations A-C andusing the inventive process were prepared, weighted and put into adessicator containing a saturated solution of ammonium chloride toinduce 80% RH. The dessicator is then placed in a 27° C. incubator. Thegum pieces are then reweighted weekly for 5 consecutive weeks. Theweight change is attributed to moisture pick-up and the % dewing iscalculated therefore as follows: ##EQU1##

The same procedure was used to test commercially available competitiveproducts.

The results of these tests, depicted graphically in FIG. 6, indicatedthat inventive formulations prepared by the inventive process showinsignificant change in % dewing after 5 weeks at 27° C./80% RH. Thecommercial doublemint product, however, showed a marked increase inmoisture pick-up between the first and second weeks and a decrease inmoisture pick-up in weeks 3-5.

It is apparent that the inventive formulations are extremely stable inthe presence of extreme humidity conditions, whereas the currentcomparable commercial chewing gums have high moisture pick-up and arerelatively unstable in this regard.

Sweating Tests

A visual determination of surface coating loss was conducted on factorywrapped product of the instant invention and compared with thecomparable competitive product. The packages are air-tight either byfin-sealing or over-wrapping with plastic and placed in an incubator at40° C. The packages are removed from the incubator weekly for 5consecutive weeks and 3 gum pieces of each package are visually examinedfor surface coating change.

The results of these tests, shown graphically in FIG. 4, indicate theinventive formulations made by

The degree of sweating was judged on the following scale:

0--No sweating

1--very slight sweating (little disappearance of coating)

2--Light sweating (same disappearance of coating)

3--Moderate sweating (disappearance of coating--degree of sticking ofwrapper due to moisture is noted)

The results of the inventive chewing gum compositions for each visualexamination was "0," indicating no sweating and no development ofmoisture, despite the extreme temperature for an extended period oftime.

The comparable competitive products showed slight sweating ("1").

EXAMPLE TWO

The following comparative example is intended to demonstrate that theinstant compositions cannot be made into chewing gum product when thetemperature of the gum base exceeds about 60° C.

Chewing gum batches containing 28% base, 65% sugar, 7% softener weremixed at temperatures of 49°, 52°, 55°, 57°, 60°, 64° and 66° C.respectively. The gum base in each case was formulated in accordancewith the inventive process. Accordingly, the base was heated to theindicated temperatures to soften it. The inventive process as outlinedin FIG. 1 was followed.

The gum bases which were softened at 49°, 52°, 55° and 60° C.respectively, exhibited good viscosity and continuity and were easilyprocessable into chewing gum formulations using the inventiveformulations A-C. Those gum bases which were heated to 64° and 66° C.respectively, exhibited a break down in fiber and elasticity and aviscosity which was too low to be processable in conventional chewinggum equipment. When attempts were made to extrude chewing gumcompositions containing these bases, they were unsuccessful due to theformation of granular chunks of gum which separated out. Those chewinggum compositions which were prepared from gum base which had been heatedabove 60° C. did not form a continuous rope when attempts were made toextrude it. Rather, granular chunks of the chewing gum compositionseparated out, causing extrusion to be unsuccessful and the result wasthe chewing gum product could not be made.

We claim:
 1. A chewing gum composition having a moisture content of upto about 0.9% by weight of the final composition, comprising a gum basewhich softens in a temperature range of about 40° C. to about 60° C., asolid water-souble sweetening agent, a softener and a liquid flavoringagent, said chewing gum having an equilibrium relative humidity valuelower than the ambient relative humidity, wherein said gum base is anelastomer selected from the group consisting of isobutylene-isoprenecopolymers, polyvinylacetate, polyisobutylene, polyvinylalcohol, chicle,jelutong, balata, crown gutta-percha, lechicaspi, sorva and mixturesthereof.
 2. The chewing gum composition of claim 1 wherein the gum basesoftens in a temperature range of about 50° to about 55° C.
 3. Thechewing gum composition of claim 1 wherein the sweetener is selectedfrom the group consisting of water-soluble sweeting agents,water-soluble artificial sweeting agents, dipeptide based sweeteners andmixtures thereof.
 4. The chewing gum composition of claim 1 wherein theflavoring agent is sorbed in the microporous channels of sphericalparticles having a bulk density of about 3.0 up to about 15.0 lbs/cu.ft.5. The chewing gum composition of claim 4 wherein the sphericalparticles are selected from the group consisting of dextrins, starchpectrin algin methyl cellulose, carboxymethyl cellulose, carboxymethylamylopectin, dextrose, fructose, maltose, lactose, dextrans, naturalgums and mixtures thereof.
 6. The chewing gum composition of claim 5wherein the sphericals are maltodextrins having a bulk density of about3.0 to about 6.0 lbs./cu.ft.
 7. The chewing gum composition of claim 6wherein the flavoring agent is a natural or synthetic material selectedfrom the group consisting of natural oils, natural essences or extracts,synthetic oils and mixtures thereof.
 8. The chewing gum composition ofclaim 7 wherein the flavoring agent is selected from the groupconsisting of peppermint oil, spearmint oil, cinnamon oil, oil ofwintergreen, fruit flavors and mixtures thereof.
 9. A chewing gumcomposition comprising from about 5 to about 65% by weight of a gum basewhich softens in the temperature range of about 40° C. to about 60° C.,a solid water-soluble sweetening agent, a softener and remainingingredients selected from conventional chewing gum additives, saidchewing gum having an equilibrium relative humidity value lower than theambient relative humidity.
 10. The composition of claim 9 wherein thechewing gum is coated prior to wrapping without regard to humidity andat ambient temperatures.
 11. The composition of claim 9 wherein thechewing gum piece is formed therefrom in a slab, stick, chunk, pillow ortablet form.
 12. A process for preparing a chewing gum composition whichcomprises:(a) softening the gum base in a temperature range of about 40°C. to about 60° C.; (b) admixing with the gum base a sweetening agentand a flavoring agent and continuing to mix until a homogenous, pliablemixture having an equilibrium relative humidity value lower than theambient relative humidity is obtained; (c) extruding the composition;(d) forming the composition into suitable chewing gum pieces withoutcooling; and (e) wrapping without prior conditioning.
 13. The process ofclaim 12 wherein the chewing gum pieces are coated with a sweetenerprior to wrapping in a relative humidity of between about 30% to about30% and at ambient temperatures.
 14. A chewing gum composition whichremains fresh for a year or more with a minimum of protective wrapping,having a moisture content of up to about 0.9% by weight and beingcapable of being extruded, formed, coated and wrapped without cooling orconditioning, said composition comprising:(a) a gum base having asoftening range of about 40° C. to about 60° C.; (b) a flavoring agent,said ingredients containing only residual moisture and being added tothe composition without additional moisture; said composition beingprepared by the process comprising:(i) softening the gum base between atemperature range of about 40° C. to about 60° C.; (ii) admixingsoftening agents, sweetening agents, and flavoring agents; (iii)extruding the composition; (iv) forming the composition into suitablechewing gum pieces without cooling; and (v) wrapping the pieces withoutprior conditioning.